Of the many reasons why social media platforms should resist pressure to “voluntarily” censor their users, one stands out: history shows that they will do it badly, taking down valuable and lawful content in the name of enforcing community standards. The result: practical speech discrimination.

Facebook’s adult content policy is a textbook example. Since its early days, the platform has banned nearly all forms of nudity. But from day one, it has created reporting processes that conflate mere nudity with sexuality, and sexuality with pornography, and has applied different standards to feminine bodies than to masculine ones.